| Autor: |
Awalludin, Anis Sofia, Ramachandran, Pravena, Jarujamrus, Purim, Lee, Hooi Ling |
| Zdroj: |
Emergent Materials; February 2022, Vol. 5 Issue: 1 p133-143, 11p |
| Abstrakt: |
The N-doped graphene quantum dots (N-GQDs) with a high quantum yield of 36.23% were synthesised through a facile hydrothermal method by using citric acid monohydrate (CA) and ethylenediamine (EDA) as the carbon and nitrogen precursors, respectively. The morphology and the surface functional group of N-GQDs were analysed by using Fourier transform infrared (FTIR) spectroscopy and high-resolution transmission electron microscopy (HRTEM) while the optical properties were observed with UV–Vis spectroscopy and photoluminescence spectroscopy (PL). The synthesised N-GQDs were reported to form in a spherical shape with an average particles size of 9.96 ± 4.4 nm based on the HRTEM analysis. Furthermore, the as-prepared N-GQDs emitted a bright blue fluorescence emission with an excitation-independent fluorescence emission at 440 nm with the excitation wavelength at 340 nm. Linear regression between fluorescence intensity and Hg2+ions at different concentrations was obtained and the limit of detection (LOD) and the limit of quantification (LOQ) were calculated as 2.46 μM and 7.45 μM, respectively. In addition, the fluorescence quenching effect that occurs in the interaction between Hg2+ions and N-GQDs corresponded to the dynamic quenching mechanism. The higher selectivity towards Hg2+ions proved that this synthesised N-GQDs could be used as a fluorescent probe to detect Hg2+ions in an aqueous solution. |
| Databáze: |
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